In 1841 Sutter bought Fort Ross near present day Bodega Bay, the only Russian settlement in Alta, California, for $30,000 on credit.  He was to pay off this debt in four years with produce and coin.  The purchase of Fort Ross brought Sutter many needed supplies such as sawn lumber, cannon, hardware, and numerous livestock.
Sutter's Fort, of course, flew the Mexican flag as they do today.  However, the 1840's were times of political turmoil in California and as more Americans arrived, Sutter maintained a friendly relationship with Americans and Mexicans alike.  In 1846, the Bear Flag Revolt in Sonoma caused a new flag, a lone star to be raised briefly over Sutter's Fort.  On July 11, 1846, Sutter and his U.S. Naval Officers replaced the Lone Star flag with the 28 star American Flag.  Capt. John C. Fremont took over command of the Fort for a short period because of Sutter's relationship with the Mexican government.  Sutter was given back his command of the fort in March of 1847.
Sutter's Fort became famous as a temporary refuge for pioneers between 1841 and 1849.  Undoubtedly inspired by his warm hosts at other forts in earlier days, Sutter provided free shelter and supplies to weary settlers.  He recruited immigrants for his settlement not only in the U.S., but also in Switzerland and Germany.
One such group helped was the Donner Party.  During the winter of 1846-1847, eighty-nine of the party were trapped in high snows at Donner Pass in the Sierra Nevada Mountains after taking an alleged shortcut.  They were taken by surprise by early snows that halted the party's advance down the mountains just west of present day Truckee.  Sutter sent several rescue parties, who brought back forty-seven survivors.  The last of which weren't reached until Spring.  They survived by eating the flesh of the dead.  The rest, forty-two members of the Donner Party, perished.  Patty Reed's Doll, an artifact from the Donner Party encampment was donated to the Fort for exhibit and has been a highlight especially for children who visit the Fort.  The Donner Party soon became a rally cry of just how arduous the journey could be and the dangers that faced early settlers.
Sutter contracted James W. Marshall in 1847 to build a sawmill on the south fork of  the American River about 50 miles east of the fort, now present day Coloma.  On January 24, 1848 Marshall was trying to deepen the tailrace of the mill and accidentally discovered gold.  Sutter tried to keep the discovery a secret and swore his men to secrecy until the mill was finished.  To support the mill, Sutter built a 50 mile long road to the mill along the banks of the American River.  On a supply run to the fort, one of the children exclaimed they had found gold.  The news was leaked and soon thousands seeking gold came to California to search for their fortune.
Many began using the fort as a wayside station for transient miners and as a trading post for miners supplies.  Unscrupulous men began swindling Sutter out of his holdings and squatters took over much of his land.  Sutter's debts began piling up so he transferred his holdings to his eldest son, John A. Sutter, Jr. who had emigrated during the summer of 1848.  The fort was sold for the meager sum of $7,000 at the end of 1849 and was no longer in Sutter's control.  Anna, Sutter's wife, came to California with the remaining children in 1850.  Sutter retired to his ranch, the Hock Farm, on the Feather River near Marysville with his family.  Sutter was long known for his immense generosity and poor business sense.  When one of his daughters was married, he threw an elaborate wedding complete with a rented steamer.  Unfortunately a year later, the daughter was divorced.  Sutter lived at the Hock Ranch until June 1865 when his home was burned down in an act of vengeful arson by a former employee.  It destroyed many of Sutter's historical accounts, journals, and objects.
Sutter then decided to go to Washington, D.C. and along with his wife tried to obtain reimbursement from Congress for his aid to emigrants; his help in colonizing the State of California (he was a member of the Monterey Convention that drew up the California State Constitution in 1849); and his losses from having his Sobrante Land Grant declared invalid by the courts.  The family settled in Lititz, Pennsylvania, in 1871 while trying to get Congress to pass a bill for his reimbursement.  On June 16th, 1880 Congress adjourned without passing a bill that would have given him $50,000 in reimbursement.  John Sutter died two days later died in a Washington D.C. hotel. He was returned to Lititz and is buried in the Moravian Brotherhood's Cemetery in Lititz, PA.  Hi wife was buried alongside him six months later.
By 1860, all that remained was his house, known today as the Central Building.  The walls and bastions were gone, much of it even pilfered.  The Native Sons of the Golden West purchased it in 1890 and donated it to the State in 1891.  Reconstruction began in 1891 based on Civil Engineer Grunsky's reconstruction plan.  The current ongoing rehabilitation is based on the Kunzul Map published in Darmstadt, Germany in 1847 to encourage German immigration to California.  This map was discovered by accident during the 1950's in San Francisco.  In 1947, Sutter Fort became a unit of the California State Park System.
This Fort was truly an interesting look into the past of the people who founded California. I highly recommend this one for everyone interested in California's past.

Good Luck! Have Fun! and Stay Safe!

Laura